Articles

Got an Itch? Preventing and Treating Poison Ivy, Oak, and Sumac

By Kari Aiello, Pharm D., BCPS.

We all know that April showers bring May flowers, but outdoor springtime activities can also bring on Poison Ivy, Oak and Sumac. These plants are the most common cause of allergic reactions, effecting 10-50 million American each year. Poison Ivy, Oak and Sumac can be found in all parts of the US except Alaska, Hawaii and deserts of the southwest.

The allergic reaction and rash that occurs from contact with Poison Ivy, Oak and Sumac is a result of urushiol, a colorless or pale yellow oil that escapes the plant. Urushiol is found in the plant leaves, stems, roots and berries and can be present for years after the plant has died. Once exposed to air, urushiol turns a brownish-black color which can be used to identify the plant. Burning of these plants, and inhaling the urushiol can cause a severe allergic reaction.

Contact can occur directly (by touching the oil yourself), indirectly (touching oil leftover on clothes, gardening tools, pets etc) or by inhaling the fumes from burned plants. Once the oil comes into contact with the skin, it can penetrate within minutes and a reaction usually appears within 12 -72 hours of contact. The delay in rash development can make people think the rash is spreading, but this is not true. Urushiol penetrates different areas of the body slower or faster, depending on skin thickness, therefore the rash can develop at different times. The typical rash often appears in streaks or patches where the plant has come into contact with the skin. The rash usually is associated with intense itching and redness, and then followed by blistering. Scratching the rash or oozing from blisters can not spread the rash, the only way it can spread is by coming in contact again with urushiol. Symptoms are worse within the first week, but can last for up to 3-4 weeks.

How to prevent Poison Ivy, Oak or Sumac:

• Learn how to identify the various plants and avoid them. (Click here for good examples of the different plants and rashes.)
  
• Do not burn the plants
  
• Wash clothes, gardening tools or anything that comes in contact with the plants, including pets. Wear gloves to protect yourself while washing.
  
• Wear protective clothing if in an area know to have Poison Ivy, Oak or Sumac
  
• If wearing protective clothing is not an option, apply OTC Ivy Block to the exposed skin areas to prevent contact

What to do if you are exposed to Poison Ivy, Oak or Sumac:

• Remove all clothes, shoes etc and wash with soap and water
  
• Wash the skin areas exposed with soap and water as soon as possible, be sure to wash under fingernails. If soap is not available, rinse with water.
  
• Washing within 10 minutes of exposure can prevent a reaction
  
• Washing within 30 minutes can help remove urushiol that has not penetrated the skin yet
  
• Tecnu is a commercial product available that can help remove the urushiol
  
• As soon as one is available, take a complete shower with soap and water, avoid baths at first because urushiol can pool in the tub and affect other non-exposed areas

How to treat mild cases of Poison Ivy, Oak or Sumac:

• Cold or tepid showers
  
• Calamine lotion with 1% phenol or 0.25% menthol applied to itchy areas as directed
  
  
  
  • Do not apply to open lesions
  
  
• Sodium Bicarbonate (Baking Soda) as a paste, cool compress or soak
  
  
  
  • Paste--mix with cool water and apply as needed
    
  • Compress--apply for 15-30 minutes and repeat as needed
    
  • Bath--add 1-2 cups to bath water and soak, then follow with paste
  
  
• Ivy dry applied as directed
  
• Hydrocortisone ointment or cream applied as directed
  
• Oral antihistamines for itching
  
  
  
  • Caution can cause sedation
  
  
• Colloidal oatmeal baths--soak for 15-20 minutes twice a day
  
• Burrows solution--dilute tablets or power, soak compress and apply to affected areas for 30 minutes four times a day
  

• Rash involves the following areas: face, eye, lips or genitals
  
• Rash shows signs of infections such as increased tenderness, oozing pus or odor
  
• Rash covers more that one-quarter of the body
  
• Initial treatment does not control symptoms

References:
1)http://www.aad.org/public/Publications/pamphlets/Poison_IvyOakSumac.htm Accessed 3/27/07.
2)http://www.emedicaine.com/script/main/art.asp?articlekey=59359&pf=3&page=2 Accessed 3/27/07.
3)http://www.webmd.com/allergies/guide/poison-ivy-oak-sumac?page=1 Accessed 3/27/07.
4)http://www.nlm.nih.gov/medlineplus/print/ency/article/000027.htm. Accessed 3/27/07.
5)Berardi, RR, McDermont JH et al. Handbook of Non-Prescription Drugs 14th ed. Washington DC, American Pharmacists Association. 2004.